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Dietary supplements of the
omega-3 fatty acid eicosapentaenoic acid (EPA) may ease
symptoms associated with depression, suggests a joint
Anglo-Iranian study.
Depression ratings were cut by 50 per cent following daily
one gram supplements of EPA, an effect similar to that
obtained by the antidepressant drug fluoxetine, according
to findings published in the Australian and New Zealand
Journal of Psychiatry.
"To our knowledge this is the first report of EPA
monotherapy in major depressive disorder," wrote the
researchers from Tehran University of Medical Sciences and
Swallownest Court Hospital in Sheffield (UK).
When the researchers provided the omega-3 supplement in
combination with fluoxetine, depression ratings were cut
by 81 per cent.
Omega-3 are polyunsaturated fatty acids (PUFAs) consumed
predominantly in the diet from fish, nuts and seeds. The
fish oil PUFAs include EPA and docosahexaenioc acid (DHA).
"Although this study had some limitation including small
sample size and lack of placebo group, the findings
suggest that EPA is safe and effective as monotherapy as
well as adjunctive treatment for unipolar major depressive
episode," wrote the researchers. "Because EPA is a dietary
supplement it may be more acceptable to patients than
antidepressants."
The study adds to a significant body of research linking
the fatty acids to a wide-range of health benefits,
including cardiovascular disease (CVD), good development
of a baby during pregnancy, joint health, and certain
cancers.
Study details
The researchers recruited 60 depressive outpatients with a
score above 15 in the 17-item Hamilton Depression Rating
Scale (HDRS). The subjects were randomly assigned to
receive a daily EPA supplement (1000 mg, supplied by
Minami Nutrition, Belgium), or 20 mg fluoxetine daily, or
a combination of the two for two months. No placebo group
was used.
At the end of the study, data from the 48 people who
finished the study showed a 50 per cent reduction in HDRS
scores for people in the EPA group, a 56 per cent
reduction in people in the fluoxetin group, and a 81 per
cent reduction in people in the combined intervention
group.
Jury still out?
Despite the positive results reported by the Anglo-Iranian
study, the overall body of science is still insufficient
to support a role for DHA and EPA for improving the
symptoms of depression, concluded a review published in
the British Medical Journal's Drug and Therapeutics
Bulletin (DTB) in February 2007.
"Despite observational evidence linking depression with
reduced intake of long-chain omega-3 fatty acids, there is
no convincing basis for using these nutrients as a [means
of alleviating] the condition," states the DTB.
After reviewing a number of randomised, double-blind,
placebo-controlled trials using EPA, DHA or both, the DTB
states that, while some studies reported positive effects,
other reported no difference between the fish oil
supplements and placebo for improving depression.
Two meta-analyses combining results of trials of fish oils
in adults both reported positive relationships. "However,
as the authors of both reviews point out, there is
significant heterogeneity among the trials, and this
undermines the reliability of the combined results."
However, the Iranian and English researcher state that
previous discrepancies may be related to the EPA and DHA
content of supplements.
"Considering the differential and sometimes potentially
opposite effects of EPA and DHA, the discrepancies among
the studies assessing omega-3 fatty acids can be explained
by the absolute, as well as relative, amounts of EPA and
DHA in supplements," they stated.
Source: Australian and New Zealand Journal of Psychiatry
Volume 42, Issue 3, Pages 192-198, doi:
10.1080/000486707018272
"Comparison of therapeutic effects of omega-3 fatty acid
eicosapentaenoic acid and fluoxetine, separately and in
combination, in major depressive disorder"
Authors: S. Jazayeri, M. Tehrani-Doost; S.A. Keshavarz, M.
Hosseini, A. Djazayery, H. Amini, M. Jalali, M. Peet |
